Draft throat for furnaces



rar-titers' .ALEXANDER LUKS, e.. ra.

Vierer-ara, an'sr'satra.

naar@ 'rrinon'r rolannuliens.

Application led July 10, 1924. Serial 110,725,223.

To all whom it may Concern:

Be it known that I, FnANoIs ALEXANDER Luns, a subject of the King of Great Britain and Ireland, residing at I4 Albert Road, Albert Parli, in the State of Victoria, Commonwealth of Australia, have invented certain new and useful Improvements in @raft Threats for Furnaces; and I do hereby declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same.

I provide an improved and economical dra-ftthroat for use in combination with the irebridge in a furnace for the purpose of promoting more complete combustion than is usual, and for reducing the production of smoke to a minimum, or approximately so. My draft throat is a po-rtable article of manufacture, the form and interior and exterior dimensions of which are fixed, subject to such provisions as may exist for adjustments, before the throat is installed in the firebridge, and the result is that the installation is rendered easy and speedy of accomplishment, the danger that workmen will err in the formation in lirebridges of draft passages of prescribed dimensions being avoided,-and other advantages are also secured.

My impro-ved draft throat is of suitable metal, or like suitable materialmetal being, compared with firebriclr, lighter, easier to transport, and less easily fracturable; and during use, with proper care, suitable metal will retain a reasonably smooth surface for a very long time, and will stand frequent cleanings to remove foulings, and secure full efficiency of operation. My throat made of suitable metal, even while it is heated as the result of use, will withstand the shocks due to the use of cleaning irons, and the firebridge will not require to be repaired at short intervals. It is thus advantageous to malte metal throats, standardizing them to suit the principal demands, and having them ready for transport and installation.

In the drawings herewith Figure I is a perspective view of one of my firebridge throats ready for installation, the inlet vbeing open.

Figure 2 shows, diagrammatically, and on a smaller scale, a longitudinal section through a boiler furnace having my draft throat.

h The draft throat has at its base l a sunici'ently broadv inlet opening 2,-shown as wideas the throat-and it has means `3*- -shown as a flap door-for regulation of the operative area of theinlet Vopening durlng use. rIhis opening acts well when it is of about the full width available in the space 4l below the grate 5, in which it will be located for the reception of heated air and gases, with some quantity of fine solid matter when the latter is present therein.

This inlet passage extends forwardly a short distance in the throat base 6; the pas sage way then extends upwardly within the` throat bodv 7 which has walls which gradually converge, so that the upper part 8 of the throat is relatively narrow. The front and back walls 9 and l0 of the body 7 are shown converging as stated, and the effect is to somewhat choke the draft and produce acceleration of its speed, so that the draft will be discharged from the throat top under pressure.

There is at ll means of discharge of the air and gases from the throat top into the furnace 12. I provide in addition when desirable a throat hood 13, which has a frontal opening so that it will deflect the escaping draft forwardly. The said hood -8 definitely prevents descent of furnace llames into the throat.

It suffices however in many cases to rely on the natural forward draft in the furnace.

Firebridge and furnace designs vary considerably in practice; hence this invention is not limited to the forms illustrated, precisely.

The inlet 2 should be well beneath the lire bar inner end 14; the throat head should be at or near the top 15 of the firebridge which will be built to contain the said throat and will be made of suitably refractory material.

The draft inlet control flap 3 has pivotal supports, 16 being apertured bars which receive the ends of a flap top bar 17 g connected to the flap is a control rod 18, which extends outside the furnace, as through a hole 19 in the front 20, and has a handle, and setting notches 22, there being a stop 23 conveniently situated, with which to engage any desired notch, to adjust the ap and regulate the draft into the throat and thus its delivery into the combustion chamber 12.

I claim: 'e

In a furnace lire bridge, a built-in metal draft throat having a forwardly extending base inlet of about the full Width of the fire bridge base and having its inlet engl about flush With the face ofthe rear Wall body fo-rrned integral Ywith the base portion and having converging front and rear WallsY and a laterally continuous outlet 1n the lireV :bridge body, the Width of said throat being Yuniform from the inlet to the outlet; a deflecting removable hood controlling the outlet and formed with a curved vvall serving by the aforesaid body and projecting from the rear Wall of the fire bridge, a flap for controlling the inlet having its other edge n Ysupported from saidV brackets and an ado'f the fire bridge, an Yupwardly extending just-able pull rod extending from the Hap to the exterior of the furnace.

In Witness whereof I have hereunto set my hand.

FRANCIS ALEXANDER LUKS.

Vitness GEORGE G. TURRI. 

